drivers/perf: arm_pmu_acpi: Fix incorrect checking of gicc pointer

Fix bogus NULL checks on the return value of acpi_cpu_get_madt_gicc()
by checking for a 0 'gicc->performance_interrupt' value instead.
Signed-off-by: Liguang Zhang <zhangliguang@linux.alibaba.com>
Signed-off-by: Will Deacon <will@kernel.org>

drivers/perf/arm_pmu_acpi.c

@@ -24,8 +24,6 @@ static int arm_pmu_acpi_register_irq(int cpu)
 	int gsi, trigger;
 
 	gicc = acpi_cpu_get_madt_gicc(cpu);
-	if (WARN_ON(!gicc))
-		return -EINVAL;
 
 	gsi = gicc->performance_interrupt;
 
@@ -64,10 +62,9 @@ static void arm_pmu_acpi_unregister_irq(int cpu)
 	int gsi;
 
 	gicc = acpi_cpu_get_madt_gicc(cpu);
-	if (!gicc)
-		return;
 
 	gsi = gicc->performance_interrupt;
+	if (gsi)
 		acpi_unregister_gsi(gsi);
 }